|−|[[Robin]] [[shaw]] Was here |+|
|−|THE [[cell]] | |
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cell]] biology) An [[autonomous]] [[self replicating]] [[unit]] (in principle) that may constitute an [[organism]] (in the [[case]] of [[unicellular]] [[organisms]]) or be a sub [[unit]] of [[multicellular]] [[organisms]] in which [[individual]] [[cells]] may be more or less specialised differentiated) for [[particular]] [[functions]]. |+|
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|−|The [[individual]] [[units]] from which [[tissues]] of the [[body]] are [[formed]]. All living [[organisms]] are composed of one or more [[cells]]. Any [[small]] compartment; the [[cells]] of a honeycomb. (biology) the [[basic]] [[structural ]] and [[functional]] [[unit ]] of all organisms ; [[cells]] may [[exist ]] as [[independent ]] [[units]] of [[life ]] (as in monads) or may [[form]] [[colonies]] or [[tissues]] as in higher [[plants ]] and animals .One [[cell]] is the lowest denomination of [[life]] thought to be [[possible]]. Most [[organisms]] consist of more than one [[cell]], which become specialised into [[particular ]] [[functions ]] towards the [[cause ]] of the [[organism ]] as a whole. [[Cells]] [[possess]] many [[structures]] [[inside]] them that contain and [[maintain]] the building [[blocks]] of [[life]] called [[organelles]]. [[Animal]] [[cells]] and [[plant]] [[cells]] [[differ]] fundamentally. |+|
. the structuraland unit of all organisms
may exist as independent of life (as in )or as in plants and animalsis into particular functions towards the cause of the organism as a whole.
|−|The [[cell]] is the [[structural]], [[functional]] & [[biological]] [[unit]] of every living [[organisms]]. It is the [[basic]] [[unit]] of [[life]]. |+|
. , , , and
|−|the smallest [[structural]] [[unit]] of an [[organism]] that is capable of [[independent]] functioning, consisting of one or more [[nuclei]], [[cytoplasm]] and various orgenelles, all are surrounded by a semipermiable [[cell membrane]]. |+|
are two types of cells: and .. . a nucleus . are , and .
|−|there are two [[main]] [[types ]] of cells: [[prokaryotes]] and [[eukaryotes]]. | |
|−|[[Prokaryotes]] are [[cells]] that contain no [[nuclei]]. almost all [[bacteria]] are [[prokaryotic]]. | |
|−|[[Eukaryotic cells]] are more [[complex]] with specialized [[organelles]] and a [[nucleus ]]. [[Plant]] and [[animal]] [[cells]] are eukariotic, as well as some [[algae]] and [[fungi]]. | |
Revision as of 13:55, 6 March 2008
(Science: Cell Biology)
1. the structural, functional and biological unit of all organisms
2. an autonomous self-replicating unit that may exist as functional independent unit of life (as in the case of unicellular organism), or as sub-unit in a multicellular organism (such as in plants and animals) that is specialized into carrying out particular functions towards the cause of the organism as a whole.
3. a membrane bound structure containing biomolecules, such as nucleic acids, proteins, and polysaccharides
- There are two distinct types of cells: prokaryotic cells (e.g. bacterial cell) and eukaryotic cells (e.g. plant or animal cell). The main difference between the two is a well-defined nucleus surrounded by a membranous nuclear envelope present only in eukaryotic cells. Despite this difference they share a number of common features: the genetic information is stored in genes, proteins serve as their main structural material, ribosomes are used to synthesize proteins, adenosine triphosphate is the main source of metabolic energy to sustain various cellular processes, and a cell membrane that controls the flow of substances into and out of the cell.